4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 upstream.
we need to take care of failure exit as well - pages already
in bio should be dropped by analogue of bio_unmap_pages(),
since their refcounts had been bumped only once per reference
in bio.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/bio.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1266,6 +1266,7 @@ struct bio *bio_map_user_iov(struct requ
int ret, offset;
struct iov_iter i;
struct iovec iov;
+ struct bio_vec *bvec;
iov_for_each(iov, i, *iter) {
unsigned long uaddr = (unsigned long) iov.iov_base;
@@ -1310,7 +1311,12 @@ struct bio *bio_map_user_iov(struct requ
ret = get_user_pages_fast(uaddr, local_nr_pages,
(iter->type & WRITE) != WRITE,
&pages[cur_page]);
- if (ret < local_nr_pages) {
+ if (unlikely(ret < local_nr_pages)) {
+ for (j = cur_page; j < page_limit; j++) {
+ if (!pages[j])
+ break;
+ put_page(pages[j]);
+ }
ret = -EFAULT;
goto out_unmap;
}
@@ -1372,10 +1378,8 @@ struct bio *bio_map_user_iov(struct requ
return bio;
out_unmap:
- for (j = 0; j < nr_pages; j++) {
- if (!pages[j])
- break;
- put_page(pages[j]);
+ bio_for_each_segment_all(bvec, bio, j) {
+ put_page(bvec->bv_page);
}
out:
kfree(pages);